Make dropdown animations respect their placement (#8292)

* Make dropdown animations respect their placement

Also fix the corner radius on the privacy dropdown button when using top placement

* Fix code style issue

app/javascript/mastodon/components/dropdown_menu.js

@@ -137,7 +137,7 @@ class DropdownMenu extends React.PureComponent {
           // It should not be transformed when mounting because the resulting
           // size will be used to determine the coordinate of the menu by
           // react-overlays
-          <div className='dropdown-menu' style={{ ...style, opacity: opacity, transform: mounted ? `scale(${scaleX}, ${scaleY})` : null }} ref={this.setRef}>
+          <div className={`dropdown-menu ${placement}`} style={{ ...style, opacity: opacity, transform: mounted ? `scale(${scaleX}, ${scaleY})` : null }} ref={this.setRef}>
             <div className={`dropdown-menu__arrow ${placement}`} style={{ left: arrowOffsetLeft, top: arrowOffsetTop }} />
 
             <ul>

app/javascript/mastodon/features/compose/components/privacy_dropdown.js

@@ -28,6 +28,7 @@ class PrivacyDropdownMenu extends React.PureComponent {
     style: PropTypes.object,
     items: PropTypes.array.isRequired,
     value: PropTypes.string.isRequired,
+    placement: PropTypes.string.isRequired,
     onClose: PropTypes.func.isRequired,
     onChange: PropTypes.func.isRequired,
   };
@@ -119,7 +120,7 @@ class PrivacyDropdownMenu extends React.PureComponent {
 
   render () {
     const { mounted } = this.state;
-    const { style, items, value } = this.props;
+    const { style, items, placement, value } = this.props;
 
     return (
       <Motion defaultStyle={{ opacity: 0, scaleX: 0.85, scaleY: 0.75 }} style={{ opacity: spring(1, { damping: 35, stiffness: 400 }), scaleX: spring(1, { damping: 35, stiffness: 400 }), scaleY: spring(1, { damping: 35, stiffness: 400 }) }}>
@@ -127,7 +128,7 @@ class PrivacyDropdownMenu extends React.PureComponent {
           // It should not be transformed when mounting because the resulting
           // size will be used to determine the coordinate of the menu by
           // react-overlays
-          <div className='privacy-dropdown__dropdown' style={{ ...style, opacity: opacity, transform: mounted ? `scale(${scaleX}, ${scaleY})` : null }} role='listbox' ref={this.setRef}>
+          <div className={`privacy-dropdown__dropdown ${placement}`} style={{ ...style, opacity: opacity, transform: mounted ? `scale(${scaleX}, ${scaleY})` : null }} role='listbox' ref={this.setRef}>
             {items.map(item => (
               <div role='option' tabIndex='0' key={item.value} data-index={item.value} onKeyDown={this.handleKeyDown} onClick={this.handleClick} className={classNames('privacy-dropdown__option', { active: item.value === value })} aria-selected={item.value === value} ref={item.value === value ? this.setFocusRef : null}>
                 <div className='privacy-dropdown__option__icon'>
@@ -226,7 +227,7 @@ export default class PrivacyDropdown extends React.PureComponent {
     const valueOption = this.options.find(item => item.value === value);
 
     return (
-      <div className={classNames('privacy-dropdown', { active: open })} onKeyDown={this.handleKeyDown}>
+      <div className={classNames('privacy-dropdown', placement, { active: open })} onKeyDown={this.handleKeyDown}>
         <div className={classNames('privacy-dropdown__value', { active: this.options.indexOf(valueOption) === 0 })}>
           <IconButton
             className='privacy-dropdown__value-icon'
@@ -247,6 +248,7 @@ export default class PrivacyDropdown extends React.PureComponent {
             value={value}
             onClose={this.handleClose}
             onChange={this.handleChange}
+            placement={placement}
           />
         </Overlay>
       </div>

app/javascript/styles/mastodon/components.scss

@@ -230,7 +230,6 @@
 
 .dropdown-menu {
   position: absolute;
-  transform-origin: 50% 0;
 }
 
 .invisible {
@@ -1634,6 +1633,22 @@ a.account__display-name {
   ul {
     list-style: none;
   }
+
+  &.left {
+    transform-origin: 100% 50%;
+  }
+
+  &.top {
+    transform-origin: 50% 100%;
+  }
+
+  &.bottom {
+    transform-origin: 50% 0;
+  }
+
+  &.right {
+    transform-origin: 0 50%;
+  }
 }
 
 .dropdown-menu__arrow {
@@ -3300,7 +3315,14 @@ a.status-card {
   border-radius: 4px;
   margin-left: 40px;
   overflow: hidden;
-  transform-origin: 50% 0;
+
+  &.top {
+    transform-origin: 50% 100%;
+  }
+
+  &.bottom {
+    transform-origin: 50% 0;
+  }
 }
 
 .privacy-dropdown__option {
@@ -3372,6 +3394,10 @@ a.status-card {
     }
   }
 
+  &.top .privacy-dropdown__value {
+    border-radius: 0 0 4px 4px;
+  }
+
   .privacy-dropdown__dropdown {
     display: block;
     box-shadow: 2px 4px 6px rgba($base-shadow-color, 0.1);